Most of us who have kept bees for several years have seen two or more queens
in a colony occasionally.  Yesterday, for example, I opened a colony,
removed the inner cover, laid a queen excluder on top of the brood box, and
before I could replace the cover TWO queens were trying to squeeze through
the excluder.  Both flew away when I tried catching them.

I suppose they might have been newly-hatched virgins, who had been roosting
under the inner cover when I removed it.  For some reason, as sometimes
seems to happen, they didn't fight.

Walter Weller
Wakefield, Louisiana